Data collected in a study of the effects of mother's communication on the infant's social referencing are analyzed. Social referencing is a process in which the infant turns to the mother for clues as to the nature of a new stimulus situation. In a laboratory setting, mother and infant are approached by an unfamiliar adult who attempts to interact with the infant. Each mother is asked to communicate one of five types of information about the stranger. Mothers either provide no information, speak to the infant about the stranger using a positive tone of voice, speak to the infant about the stranger using a neutral tone of voice, greet the stranger using a positive tone of voice, or greet the stranger using a neutral tone of voice. Another variable explored is the reaction of infants with different temperaments in the same situation. Subjects are 87 mothers and their ten-month-old infants.